I am working on a project with different reinforcement in x and y directions. This means that the stiffness is different. Which means that the moments will be distributed differently along the x and y (mx and my).
I have tried this in my linear analysis:
+PROG ASE urs:9 $ Linear Analysis
HEAD Calculation of forces and moments
PAGE UNII 0
CTRL OPT WARP VAL 0
$Modificer stivheder i x retning GRP2 NO 1 QEMX 0.5
ECHO MAT EXTR
So far i’ve found that the GRP2 and QEMX changes the stiffness, but is there anyway i can see if it has changed the elastic modulus? Or does the QEMX command work by just setting the stiffness in x to 50 (in this case with 0.5) % of the y direction?
Also, when i use ECHO MAT EXTR, where is this matrix printed to? i cant seem to find it in the result viewer.
GRP2-Definitions work only in the particular ASE-calculation and the only confirmation of these definitions is this particular ASE-protocol.
ECHO MAT shows only the regular overall-(AQUA)-MAT-values, not the possible group-related runtime-modifications.
But: what means “different reinforcement in x and y directions”? If you want to calculate with realistic/cracked stiffness of reinforced concrete, this is IMHO not a good approach.
As the use of QEMX is intended the example “steel_composite_orto.dat”.
Thanks for the answer. Im not sure i understand it though.
Instead of steel, its just a concrete beam. This beam is anisotropic, because of the reinforcement. How would you go about modelling that? The model, as is, distributes the bending moments equally in each direction. This is not correct. So i thought reducing stiffness in one direction would come closer to the actual behaviour of the beam.
Stiffness-manipulation with GRP2 is mostly intended for mixed models (beam- and quadelements with (partial) doubled areas from beam-cross-sections und quads) with othogonal load-bearing-behaviour / orthogonal different design (beams longitudinal, quads transversal). This doubled areas/stiffness should then be corrected with GRP2.
If you don’t have such a mixed model, then it is IMHO not necessary to tricking the stiffness. Also not for anisotropic reinforcement, especially not for material-linear calculation.
(If you have anisotropic material like masonry, then you can simplified work with anisotrop quad-thickness (MSHA: QUAD tx ty txy td)).
In your case maybe a material-nonlinear analysis works better (a ASE-instance: “a2_nonlinear_slab.dat”).
Thanks for you answer.
For some reason, i cannot open/get acess to any of the .dat files from the manual.
I will check out MSHA: QUAD
I did a test with GRP2, and it seemed to work as i wanted it too for a 2D slab. When i reduce the stiffness x-direction, mx decreases, and my increases.
What is your reasoning for saying that it is not necessary to change stiffness?